<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>CSS实现的拖拽留言板卡片功能</title>
</head>
    <style>

        /* 
        原理
        div{
            width: 100px;
            height: 100px;
            border: 5px solid deeppink;// 最好注释这行
            resize: both;
            overflow: hidden;
            position: relative;
        }
        div::-webkit-resizer{
            background-color: transparent;
        }
        div::before{
            content: '';
            width: 20px;
            height: 20px;
            border-radius: 50%;
            background-color: deeppink;
            position: absolute;
            bottom: 0;
            right: 0;
        } */
        #main{
            position: absolute;
            display: inline-block;
        }
        #resize{
            content:'';
            width: 20px;
            height: 20px;
            border-radius: 50%;
            resize: both;
            overflow: hidden;
            position: relative;
            /* background-color: deeppink; */
            z-index: 1;
        }
        #resize::-webkit-resizer{
            background-color: transparent;
        }
        #content{
            box-sizing: border-box;
            width: 400px;
            height: 500px;
            background-color: yellow;
            padding: 30px;
            font-family: "marker felt","comic sans ms",sans-serif;
            font-size: 24px;
            position: absolute;
            right: -380px;
            bottom:-480px;
            &::after{
                content: '';
                width: 20px;
                height: 20px;
                border-radius: 50%;
                background-color: red;
                position: absolute;
                top:0;
                left: 0;
                
            }
        }
    </style>
<body>
    <!-- 
        原理
        <div></div> -->

    <div id="main">
        <div id="resize"></div>
        <div id="content" contenteditable="true">helle ,world !!!!!xxxxxxxxxxxxx xxxx</div>
    </div>
</body>
</html>